A major cyberlocker described by the MPAA / RIAA-affiliated International Intellectual Property Alliance as an “infringing distribution hub” appears to be in serious trouble. Filesonic, previously listed among the top 10 largest file-sharing sites in the world, was badly affected by the Megaupload shutdown and lost huge amounts of traffic in 2012. During the last 48 hours it simply ceased to function.

In the wake of the January shutdown of Megaupload, many of the Internet’s leading cyberlocker services changed their business models in the hope they could avoid a similar fate.

One such site, Hong Kong-based Filesonic, took the drastic measures of discontinuing both their rewards program and all third-party sharing. In the file-hosting world their decisions were a pretty big deal. At the time Filesonic was one of the top 10 file-sharing sites on the Internet, with a quarter billion page views a month. As can be seen from the Alexa graph below, the effects were dramatic.

Despite the efforts of Filesonic to stay out of the copyright infringement spotlight (in December 2011 the company had partnered with anti-piracy company Vobile), in February 2012 the International Intellectual Property Alliance reported Filesonic to the USTR. IIPA, who count the MPAA and RIAA as members, described Filesonic as an “infringing distribution hub.”

But today, six months on, it appears something is seriously amiss with this former giant of the file-sharing world. For two days Filesonic has been completely unreachable via its .com domain after changes were made to its DNS settings.

The site does have plenty of other domains with different extensions, but strangely none of those have been updated to include the same settings as the .com domain. For example, Filesonic.net, .ch, and .jp are all registered to Earnwell Hong Kong LTD, the company behind Filesonic. However, Filesonic.com is now registered to Seychelles-based Renovatio Management Limited.

While the .com domain is completely broken and no longer uses the traditional Filesonic DNS servers, the other domains do resolve to the Filesonic site but it is completely non-functional.

In order to find out exactly what’s happening with Filesonic, TorrentFreak attempted to contact the file-hoster in three different ways but we received no response. We also contacted Renovatio Management but they didn’t respond either. The only people we could get to say anything at all was Filesonic’s hosting company, but they told us they would not discuss their client’s business.

This year has been a miserable one for Filesonic, and it’s still not over. Aside from its traffic woes and now unexplained disappearance, along with Oron (another cyberlocker that has simply vanished), Filesonic is being sued by adult entertainment company Flava Works. The company does not yet appear to have responded to the lawsuit.

The disappearance of both Oron and now Filesonic raises plenty of questions, but perhaps what is most unusual is the complete lack of communication with their customers. A simple message on the sites’ homepages would suffice, but neither filehost has obliged. Exactly why is anyone’s guess.